Inspired by the video to Lacquer's song "Behind", I decided to have a go at making time-lapse videos of my bicycle journeys. Here is information on the technical side of the venture, and below are the movies. This is a work in progress, so do check back.
The Tour de Salisbury
The Wylye Valley
The camera used here is a Minolta Dimage 2300, which I bought cheaply off eBay. I needed some way of making it take photos automatically. I knew that the 555 timer chip (a simple 8-legged silicon chip) was capable of doing this sort of thing, and after searching on Google found quite a few websites where people had done similar things, usually in order that they could send cameras up into the air using kites or model aeroplanes (search for 'kite aerial photography'). The problem was that the shutter mechanism of this camera wasn't a simple switch like it was here, for example - instead it was one of the two-stage switches where you press it part-way to focus and then all the way to take the picture. Once I pulled the camera apart, I found the various contacts that led to the shutter button and with a piece of wire could make the camera take pictures. However, it involved linking three contacts in a specific order and then disconnecting them before another picture could be taken, and although I could, using this circuit, make the camera focus every few seconds, I couldn't make it take photos.
I spent quite a while wondering how I could get round this, and was on the verge of designing a much more complicated circuit using two timers when I realized that my camera had the option of being remotely controlled. Getting hold of a remote control was easy, and to my joy I found that the shutter button on it WAS just a simple switch. I was able to rip the top off this and glue the 555 chip along with 2 resistors and 2 capacitors onto the top. The circuit took its power and sent its pulses to the two contacts under the button, earthing back to the battery. I stuck the modified remote to the side of the camera and extended the infra-red LED on wires so it could reach the receiver on the front of the camera. The thing's a bloody mess, but it does the job!
The circuit does have a trimpot instead of one of the resistors, which in theory allows me to alter the timing between shots. However, I've found that with this camera the best thing is to set the timer so it is effectively pressing the shutter button over and over very quickly. Given the time taken for the camera to focus, read light levels, take the picture and then transfer it to the CF card, this rapid shutter-pressing means I'm taking a picture about once every 8-10 seconds, which is the best I can do. I might have wanted it slightly faster, but to be honest it's not a bad speed and I'm pretty happy with it.
UPDATE: I managed to improve this! The remote control had two buttons - one that made the camera take a picture and one that made it take a picture after a 2 second delay. It seems my circuit, although rigged up to the 'immediate photo' button, was triggering the 2s delay system. I re-jigged things and now have it taking photos without the delay. Pictures are now being taken every 7s. This really seems to be the fastest this camera can manage - it starts taking each photo as soon as the data transfer to the CF card is complete. I'm using a fast CF card too, so the transfer seems to be the limiting factor. 7 seconds should be good enough though.